How to Clean Copper and Prevent Future Tarnishing

Copper pieces add warmth and elegance to any room. However, over time, they're bound to lose their luster, developing a layer of tarnish. Even in optimal conditions (a cool, dry setting out of direct sunlight), tarnish can't be avoided, and while it isn't harmful, it can be unsightly. Luckily, it's easy to polish away, but you'll want to take extra care when it comes to cleaning copper—if you scrub too hard, you can scratch the metal and remove the finish. Our experts help you learn how to clean copper using the right cleaning supplies to safely restore your most beloved pieces. 

How Often to Clean Copper 

How frequently you clean copper depends on the specific item and its intended use. "Copper tends to develop a natural patina over time, which can be desirable for certain decorative pieces or architectural elements," says Alicia Sokolowski, president and co-CEO of AspenClean, a manufacturer of green cleaning supplies and provider of in-home cleaning services. "However, if you prefer to maintain the copper's original shine, regular cleaning is necessary.”

Indoor Decorative Pieces

Items strictly for indoor use, like copper vases or ornaments, may require cleaning every few months or as needed. "Monitor their appearance and clean them when you notice a dull or tarnished surface," says Sokolowski. 

Outdoor Pieces

Items exposed to the elements, like copper architectural details or sculptures, may need more frequent cleaning. "Factors like weather conditions and pollution levels can affect copper's patina," says Sokolowski. "You may need to clean outdoor copper items every few weeks or months to prevent excessive tarnishing.”

Cookware and Kitchen Utensils 

Clean copper cookware and utensils that come into direct contact with food after every use. "Use a natural cleaner or a natural solution like lemon juice and salt to remove the tarnish and maintain their appearance," says Sokolowski. 

Materials Needed

Copper can be cleaned using natural ingredients you likely already have on hand. Here are the supplies you'll need (depending on the method used) to tackle this project.

• Lemon
• Salt 
• Microfiber towel(s)
• White vinegar
• Ketchup
• Flour
• Soft-bristled brush

How to Clean Copper With Lemon and Salt 

Cleaning copper with lemon and salt is a natural and effective method ideal for copper cookware, but it may not be suitable for all types of copper objects. "Avoid using this method on items with delicate or sensitive finishes, valuable antiques, or items with decorative elements that scrubbing could damage," says Sokolowski. 

1. Cut a fresh lemon in half and squeeze the juice into a bowl, removing any seeds. 
2. Sprinkle a generous amount of table salt or coarse salt onto half the lemon. 
3. Gently rub the salted lemon onto the tarnished areas of the copper item. 
4. Repeat with the remaining lemon, if needed. 
5. After treating all tarnished areas, rinse the copper with water to remove lemon juice and salt residue. 
6. Dry with a microfiber cloth. 

How to Clean Copper With Vinegar and Salt

Another natural cleaning agent for copper is vinegar. "It's worth noting that vinegar is an acidic solution, and prolonged exposure or excessive use can potentially dull or etch certain types of copper finishes," says Sokolowski. "Always test the vinegar solution on a small, inconspicuous area of the copper item before applying it to the entire surface."

1. Mix equal parts white vinegar and water and 1 tablespoon of salt.  
2. Dip a microfiber cloth into the vinegar solution, ensuring it's well-saturated but not dripping. 
3. Gently rub the cloth onto the tarnished areas of the copper item, applying light pressure and moving in a circular motion. 
4. For stubborn tarnish, let the solution sit on the copper surface for a few minutes before scrubbing. 
5. After treating all tarnished areas, rinse the copper with water to remove any vinegar residue.
6. Dry with a microfiber cloth.

How to Clean Copper With Ketchup 

If vinegar doesn't work, try ketchup. "The acid in the tomatoes will remove the tarnish," says Leslie Reichert, a green cleaning coach and the author of The Joy of Green Cleaning. 

1. Cover the surface of the copper item with ketchup. 
2. Use a microfiber cloth to gently remove any tarnished areas on the copper item.
3. After rubbing ketchup around the item, thoroughly rinse it with water to remove any ketchup. 
4. Dry with a microfiber cloth.

How to Clean Badly Tarnished Copper 

If you have copper pieces that are badly tarnished, Sokolowski says to try this heavy-duty cleaning solution. 

1. Mix equal parts salt and flour in a bowl. 
2. Slowly add vinegar or lemon juice to the mixture and stir until a thick, smooth paste forms. 
3. Apply the paste to the heavily tarnished areas of the copper item.
4. Let the paste sit for approximately 30 minutes to one hour.
5. Using a soft-bristled brush, scrub the tarnished areas with the paste, applying light pressure and moving in a circular motion. 
6. After treating all tarnished areas, rinse the copper with water to remove any residue from the cleaning paste.
7. Dry with a microfiber cloth.

How to Prevent Copper From Tarnishing 

First, it's helpful to understand why copper and other metals tarnish. "Copper tarnishes over time due to a natural chemical reaction between copper and the surrounding environment," says Sokolowski. Initially, this causes a layer that may appear reddish-brown. Over time, the oxide layer can continue to react with the air and cause a greenish-blue patina. While the main reason copper tarnishes is from natural oxidation, the process can be accelerated by other factors, like moisture and pollutants. 

Apply Oil

Prevent tarnish by wiping a light coat of baby or mineral oil over your copper pieces right after cleaning. "Copper starts to tarnish as soon as it's cleaned," says Reichert. "The oil will seal the copper from the air and slow down the tarnishing process."

Keep Copper Dry

Moisture accelerates the tarnishing process, which is why drying your copper items immediately after cleaning is important. "After cleaning or when not used, ensure that copper items are thoroughly dried before storing them," says Sokolowski.

Store Properly

Whether you keep your copper items on display or hidden away, proper storage is key. "If you're displaying copper items, consider placing them in areas with minimal exposure to direct sunlight, excessive humidity, or pollutants," says Sokolowski. "Ultraviolet light can accelerate tarnishing, so protecting copper from prolonged exposure to sunlight can help preserve its appearance."

If you keep your copper pieces in a cabinet or storage container, you may want to wrap them using acid-free tissue paper or cloth to help prevent tarnishing caused by contact with other materials.

Limit Humidity

Avoid leaving copper objects in humid environments. "High humidity or direct contact with water can accelerate the oxidation process, leading to faster tarnishing of copper," says Sokolowski. Additionally, certain air pollutants from industrial emissions or certain cleaning products can react with copper and speed up tarnishing.

Add Wax Coating

Create a barrier between the copper piece and air using a thin layer of wax coating, like carnauba wax or a commercial copper protectant. A wax coating will slow down the rate of tarnishing, and you can still clean and polish the waxed piece. Wax or a commercial copper protectant with wax works well on copper jewelry, decorative items, and it's also recommended for copper sinks.